There are two main types of potato guns. Combustion guns use a flammablefuel and igniter to move an object. Another type uses compressed air. Potato guns are usually built of PVC or ABS (a type of plastic) piping.

the operator will put a projectile into the barrel. A ramrod is often used to push it all the way down to the end of the barrel. The projectile must fit tightly into the barrel so that the pressure of the expoding fuel is strong enough to move it. This is why potatoes are often used. With a large potato, the unneeded part of potato would be cut off when the potato is forced into the barrel. This creates a projectile that is almost the exact size as the inside of the barrel.

The cap is removed and a flammable fuel is put in the combustion chamber. Aerosolhairspray is a popular fuel because it ignites easily. Once fuel is added, the cap is replaced.

The cannon is pointed at its target and the igniter triggered. This causes the fuel to burn. The rapidly expanding gasses force the projectile out of the end of the barrel.

A potato cannon can move a 2" diameter potato projectile over 100 yards at a speed of 40 mph. This makes potato guns dangerous.

the operator will put a projectile into the barrel. A ramrod is often used to push it all the way down to the end of the barrel. The projectile must fit tightly into the barrel so that the pressure of the air is strong enough to move it.

The air reservoir is filled by connecting it to a compressed air source. The release be closed at this time.

the cannon is aimed and the release is pulled. This causes the compressed air to rush into the barrel. The high pressure forces the projectile out of the end of the barrel.

A air powered potato cannon is much stronger than a combustion cannon. A combustion potato gun will launch projectiles at a pressure of about 10-20 psi. Air powered guns often use pressures over 100 psi.